She and her husband, Frank Sianez, said they thought for years about switching to solar but shied away from the upfront cost, which can often run into tens of thousands of dollars.

"I was always reluctant because of that," said Frank Sianez.

So instead the couple decided to sign a power-purchase agreement that means they will essentially lease a system and pay the installation company based on how much electricity they use.

"The offer that they gave me, this particular company, was no cost for the solar panels, no cost for the installation," said Frank Sianez. "And in replacement of that reduction of cost, we simply pay them for the next 20 years."

The Sianezs will pay Solar City 15 cents for each kilowatt-hour, a rate equal to PG&E's lowest tier.

Since turning on the system Wednesday, they say they have monitored savings of about $3.

"While $3 might not sound like a whole lot, if you compound that by 365 days, you're saving over a $1,000 each year," said Frank Sianez.

The Sianez's will still see rate increases, but they will be fixed at 2.9 percent a year.

Solar City, which installed the Sianezs system, said rate certainty is one of the reasons its business is booming.

However, Shirley Montalvo, a senior energy consultant for Solar City, said solar is not always right for every home.

"Actually, it doesn't make sense if your roof is shaded. You need the sun to go solar. So if your roof is shaded, we can't do anything about shade," said Montalvo.

The Sianezs said they were fortunate because their roof is perfectly oriented to receive the maximum amount of sunshine.

The federal government offers a tax incentive worth 30 percent of system's cost.

However, homeowners benefit from the incentive only if they purchase the system.